“…To test for the high number of drugs and metabolites in hair samples, pharmacotoxicology laboratories are required to update analytical procedures, in order to achieve rapid, simple and sensitive analyses with reduced sample preparation and instrumental processing, to finally increase overall sample-throughput. Different methods have been proposed for testing class-specific groups of compounds [66,69,[72][73][74][77][78][79], but only a few articles describe extensive analysis of multiclass drugs [60,61,[63][64][65]67,68,75,76,80] with some including also methods for THC quantification [62,70,71].…”